ops_optimizer.c File Reference

#include "libavutil/avassert.h"
#include <libavutil/bswap.h>
#include "libavutil/rational.h"
#include "ops.h"
#include "ops_internal.h"

Go to the source code of this file.

Macros
#define	RET(x)
	Copyright (C) 2025 Niklas Haas. More...

Functions
static bool	op_type_is_independent (SwsOpType op)
static unsigned	merge_comp_flags (unsigned a, unsigned b)
void	ff_sws_op_list_update_comps (SwsOpList *ops)
	Infer + propagate known information about components. More...
static int	exact_log2 (const int x)
static int	exact_log2_q (const AVRational x)
static bool	extract_scalar (const SwsLinearOp *c, SwsComps prev, SwsComps next, SwsConst *out_scale)
	If a linear operation can be reduced to a scalar multiplication, returns the corresponding scaling factor, or 0 otherwise. More...
static bool	extract_constant_rows (SwsLinearOp *c, SwsComps prev, SwsConst *out_clear)
static bool	extract_swizzle (SwsLinearOp *op, SwsComps prev, SwsSwizzleOp *out_swiz)
int	ff_sws_op_list_optimize (SwsOpList *ops)
	Fuse compatible and eliminate redundant operations, as well as replacing some operations with more efficient alternatives. More...
int	ff_sws_solve_shuffle (const SwsOpList *const ops, uint8_t shuffle[], int size, uint8_t clear_val, int *read_bytes, int *write_bytes)
	"Solve" an op list into a fixed shuffle mask, with an optional ability to also directly clear the output value (for e.g. More...

Variables
static const unsigned	flags_identity = SWS_COMP_ZERO | SWS_COMP_EXACT

Macro Definition Documentation

RET

#define RET

(

x

)

Value:

    do {                                                                       \
        if ((ret = (x)) < 0)                                                   \
            return ret;                                                        \
    } while (0)

Copyright (C) 2025 Niklas Haas.

This file is part of FFmpeg.

FFmpeg is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.

FFmpeg is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with FFmpeg; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

Definition at line 28 of file ops_optimizer.c.

Function Documentation

op_type_is_independent()

static bool op_type_is_independent ( SwsOpType  op )

static

Definition at line 36 of file ops_optimizer.c.

Referenced by ff_sws_op_list_optimize().

merge_comp_flags()

static unsigned merge_comp_flags ( unsigned  a, unsigned  b  )

static

Definition at line 67 of file ops_optimizer.c.

Referenced by ff_sws_op_list_update_comps().

ff_sws_op_list_update_comps()

void ff_sws_op_list_update_comps

(

SwsOpList *

ops

)

Infer + propagate known information about components.

Called automatically when needed by the optimizer and compiler.

Definition at line 75 of file ops_optimizer.c.

Referenced by ff_sws_op_list_optimize().

exact_log2()

static int exact_log2 ( const int  x )

static

Definition at line 305 of file ops_optimizer.c.

Referenced by exact_log2_q().

exact_log2_q()

static int exact_log2_q ( const AVRational  x )

static

Definition at line 314 of file ops_optimizer.c.

Referenced by ff_sws_op_list_optimize().

extract_scalar()

static bool extract_scalar ( const SwsLinearOp *  c, SwsComps  prev, SwsComps  next, SwsConst *  out_scale  )

static

If a linear operation can be reduced to a scalar multiplication, returns the corresponding scaling factor, or 0 otherwise.

Definition at line 328 of file ops_optimizer.c.

Referenced by ff_sws_op_list_optimize().

extract_constant_rows()

static bool extract_constant_rows ( SwsLinearOp *  c, SwsComps  prev, SwsConst *  out_clear  )

static

Definition at line 352 of file ops_optimizer.c.

Referenced by ff_sws_op_list_optimize().

extract_swizzle()

static bool extract_swizzle ( SwsLinearOp *  op, SwsComps  prev, SwsSwizzleOp *  out_swiz  )

static

Definition at line 380 of file ops_optimizer.c.

Referenced by ff_sws_op_list_optimize().

ff_sws_op_list_optimize()

int ff_sws_op_list_optimize

(

SwsOpList *

ops

)

Fuse compatible and eliminate redundant operations, as well as replacing some operations with more efficient alternatives.

Definition at line 412 of file ops_optimizer.c.

ff_sws_solve_shuffle()

int ff_sws_solve_shuffle	(	const SwsOpList *	ops,
		uint8_t	shuffle[],
		int	size,
		uint8_t	clear_val,
		int *	read_bytes,
		int *	write_bytes
	)

"Solve" an op list into a fixed shuffle mask, with an optional ability to also directly clear the output value (for e.g.

rgb24 -> rgb0). This can accept any operation chain that only consists of the following operations:

• SWS_OP_READ (non-planar, non-fractional)
• SWS_OP_SWIZZLE
• SWS_OP_SWAP_BYTES
• SWS_OP_CLEAR to zero (when clear_val is specified)
• SWS_OP_CONVERT (integer expand)
• SWS_OP_WRITE (non-planar, non-fractional)

Basically, any operation that purely consists of moving around and reordering bytes within a single plane, can be turned into a shuffle mask.

Parameters

ops	The operation list to decompose.
shuffle	The output shuffle mask.
size	The size (in bytes) of the output shuffle mask.
clear_val	If nonzero, this index will be used to clear the output.
read_bytes	Returns the number of bytes read per shuffle iteration.
write_bytes	Returns the number of bytes written per shuffle iteration.

Returns

The number of pixels processed per iteration, or a negative error code; in particular AVERROR(ENOTSUP) for unsupported operations.

Definition at line 774 of file ops_optimizer.c.

Referenced by solve_shuffle().

Variable Documentation

flags_identity

const unsigned flags_identity = SWS_COMP_ZERO | SWS_COMP_EXACT

static

Definition at line 66 of file ops_optimizer.c.

Referenced by ff_sws_op_list_update_comps().